Fluid compressor



E. A. RIX

FLUID COMPRESSOR July 17, 1928. 1,677,369

Filed June 13, 1927 H iiiiiiiz ATTORNEYS.

Patented July 17,1928.

first EDWARD A. RIX, OF OAKLAND, CALIFORNIA.

FLUID COMPRESSOR.

Application filed June 13,

much as possible of this compressed charge through a flash port into the main cylinder at the end of the intake stroke, the result being that the main cylinder is filled at the beginning of the compressing stroke with air or gas at a pressure 01' about three pounds or more instead of an atmospheric pressure or slightly less, as in ordinary compressors.

Actual experience has shown that a gain the diflerential piston is obtained. This is due to the instataneous closure of the main inlet valve as soon as the flash port opens and the differential piston discharges its contents into the main cylinder.

It is'evident that the relative volumes of the main and the difi'erential cylinder, as disclosed in my former patent above referred to, must be a fixed quantity and the capacity of the small reservoir into which the differential piston compresses its contents has, accordingly, been a fixed quantity equal to one-half the contents of the diflerential cylinder, so as to obtain about fifteen pounds gauge pressure at the end of the stroke. Experience has shown, however, that while at all atmospheric altitudesand temperatures the relative additional volume given by the differential piston is constant that a still greater volume may be given by the following improvements in construction:

1st. By making the differential displacement of the piston somewhat larger in proportion to the main cylinder. 7

2nd. By making it possible to vary the volume of the reservoir into which the differential piston discharges.

3rd. To-flash the contents of the reservoir into the main cylinder through ports formed in the piston instead of through flash ports formed in the main cylinder.

of more than the one-third expected from,

1927. Serial No. 198,391.

, 4th. By placing a by-pass pipe and valve between the super-charging reservoir pf each cylinder of a duplex compressor with a plain stop valve in the pipe to regulate the amount of by-pass.

These features constitute the -improvements andobjects of the present application and they will be fully described in detail by referring to theaccompanying drawings'in which:

Fig. 1 isfa central vertical section of one of the cylinders of a duplex fluid compressor.

Fig. 2 is a side elevation ofthe cylindersof a'duplex'fluid compressor.

Referring to the drawings in detail and particularly Fig. 2,11 indicates an'air compressor cylinder, A the head of the cylinder,'1 and 2, inlet and discharge valves respectively, 4 a main piston and L a differential piston formed by the difference in area between the main piston and the trunk L. Reciprocating motion is imparted to thepiston in any suitable manner, for-instance through a connecting rod3.- The cylinder may be water jacketed, as indicated at 8, and it is in this instance provided with an auxiliary supercharger reservoir F. Communicating with this reservoir'is' an inlet valve K and-a cylinder B. V This cylin der is provided with a piston E and a threaded rod which extends through a head secured on the outer end of the cylinder. This rod is provided with a hand wheel C and movement of the piston E to or away from the chamber F is controlled by rotation of the hand wheel C and the threaded rod. The main piston 4 carries a valve H and flash ports G. The piston is also provided with a flange P and with ring grooves and rings of the usual type.

the auxiliary super-charging chamber F through the valve K. This body of air is compressed during'th'e downward stroke of the piston and it is by-passed or flashed into the main cylinder chamber J when the ports G register with the auxiliary chamber. In-

let valve 1 will, of course, also admit air during the downward stroke of the piston, but the air admitted is usually slightly less than amospheric pressure. The air conipres-sed and flashed through the port G is added to the volume admitted through the valve 1 and a pressure of from three to five pounds is obtained at the endjof the downward stroke of the piston. This charge is' In natural operation air is admitted to compressed and discharged through the valve 2 during the upward stroke. of the 1 piston and a material increase in the volume 1 and the volume may also be'decreased by by-passing air from one auxiliarychamber F to another, as illustrated in Fig. 2. In

this instance a duplex. super-charger compressor is shown, that 1sa two-cylinder unit.

Each intermediate chamber is providedwith a cylinder B and these cylinders are connected bymeans of a pipe 9 and a valve D. .Thns by 'full opening the valve D the final discharge rom the compressor is reduced to aminimum, as super-charging air Will not be added to the cylinders J as the air delivered to the auxiliary chambers F by means of the differential pistons will merely surge back and forth through the pipe 9 and the valve D. On the other hand,

,it was fixed and not variable.

if itis desired ,to increase the discharge fromthe valve 2, it is merely necessary to partially or fullyiclose the valve D. Partialclosing of the valve gradually increases the final discharge from the compressor, while total closing of the valve produces the maximum discharge In the original patent previously referred to, the differential I displacement was made as nearly average to all conditions'as possible because The compressor shown in the present invention is designed to take care of a maximum for all requirements, and if less than the maximum is required, it is accomplished by increasing the volume or capacity of the auxiliary chambers F. It is evident that given a fixed displacement by the differential piston, that the amount of this volume which will be flashed into the main cylinder at the end of the stroke will be determined by the super-charger reservoir and the length of time the flashing port G remains open. The greater the pressure in the auxiliary chamber F, the more air will be flashed into the ain cylinder J. Hence, by mechanically increasing or decreasingthe volume of the auxiliary chamber F, as bymeans of the 7 piston E, it is possible to increase or decrease the, pres-sure and hence the volume or amount of air flashed into the main cylinder,

This adjustment may be made by hand.

asdescribed, to suit existing conditions of altitude or atmospheric temperature.

The placing. of the flash ports G in the piston is also an important feature, as it is evident that a flash port in the cylinder such as disclosed in my former patent, which is positioned at the end of the intake stroke, will reduce the compressing stroke by the hei ht or width of the flash port.

This loss of stroke is obviated in the present instance by placing the flash port and a valve in. the piston. This change in the position of the flash port is of further importance, as it does away with the former necessity. of riding the piston rings over the flash ports when placed in the cylinder.,

.lVhen the compressor has been arranged and adyusted by varying the volume 1n the auxiliary chamber to bring about the greatest etliciency, the adjustable parts may be through a range of approximately tWentyfive or thirty five per cent.

Compressors of the type here. illustrate d are usually arranged in duplex or two-cyl inder units. Each cylinderis Water acketed and as the intermed ate chambers F are disposed below the water jackets, it is pos sible to carry them completely around each cylinder. This is also important as it s'uni-f larly permits the flash ports to be carried completely around the pistons, thus increas, ing the areas ,of the same. lVhile the air.

for super-charging purposes will in most instances be admitted through valves of the poppet type, such as shown at K, it may also be admitted to the chamber F through ports such as shown'at M, N, and O. l-Vhen the air is admitted through the ports N and 0 it is taken from the atmospheric exterior of the cylinders, but if the air taken through the ports M and 0, 'port N may be eliminated, as the air will then be admitted through the crank case. Any one of the arrangements shown is feasible and while other features of the invention are more or less specifically illustrated, I Wish it understood that various iii! E- ii Wit changes may be resorted to within the scope of the appended claims; similarly, that'the materials and finish of theseveral parts emchamber and discharge the same into the main chamber, only at ornear the beginning of the compression stroke and means for Varying the pressure of the fluid in the auxiliary chamber.

2. A fluid compressor comprising in combination a cylinder and a piston in said cylinder dividing the same into a main compression chamber and an auxiliary compression chamber, said piston being operable during the major portion of the extension stroke to compress fluid in the auxiliary chamber and discharge the same into the main chamber, only at or near the beginning of the compression stroke and means for varying the capacity of the auxiliary chamber.

3. A fluid compressor comprising incombination a cylinder and a piston in said cylinder dividing the same into a main compression chamber and an auxiliary compression chamber, said piston being operable during the major portion of the extension stroke to compress fluid in the auxiliary chamber and discharge the same into the main chamber, only at or near the beginning of the compression stroke and an adjustable displacement member in communication with the auxiliary chamber to vary the capacity thereof.

4. A fluid compressor comprising in combination a cylinder and a piston in said cylinder dividing the same into a main compression chamber and an auxiliary compression chamber, said piston being operable during the major portion of the extension stroke to compress fluid in the auxiliary chamber and discharge the same into the main chamber, only at or near thebeginning of the compression stroke, and means whereby a portion or all of the fluid compressed in the auxiliary chamber may be discharged therefrombefore discharging the same into' the main chamber.

5. A fluid compressor comprising in combination a cylinder and a piston in said cylinder dividing the same into a main compression chamber and an auxiliary compression chamber, said piston being operable during the major portion of the extension stroke to compress fluid in the auxiliary chamber and discharge the same into the main chamber, only at or near the beginning of the compression stroke, a cylinder-like extension in communication with the auxiliary chamber, a piston mounted in said extension and means whereby the p'bsition of the piston within said extension may be adjusted to increase or decrease the capacity of the auxiliary chamber.

6. A fluid compressor comprising in combination a cylinder and a piston in said cylinder dividing the same into a main compression chamber and an auxiliary compression the major portionof the extension strokev to.

compress fluid in the auxiliary chamber,- said piston having ports formed therein formingcommunication between the main compression chamber and the auxiliary chamber only at or near the beginning of the compression stroke and a valve in said pistonadapted toopen and close said ports.

7. A fluid compressor comprising in combination a cylinder and a piston in said cylinder dividing the same into a main compression chamber and an auxiliary compression chamber, said piston being operable during the major portion of the extension stroke to compress fluid in the auxiliary chamber, said piston having ports [formed therein forming communication between the main compression chamber and the auxiliary chamber only'at or near the beginning of the compression stroke, a valve in said piston adapted to open and close said ports, and means for admitting fluid to the auxiliary chamber during the compression stroke of the piston.

8. A fluid compressor comprising in combination a cylinder and a piston in said cylinder dividing the same into a main compression chamber and an auxiliary compression chamber, said piston being operable during the major portion of the extension stroke to compress fluid in the auxiliary chamber, said piston having ports formed therein forming communication between the main compression chamber and the auxiliary chamber only at or near the beginning of the compression stroke, a valve in said piston adapted to open and close said ports, means for admitting fluid to the auxiliary chamber during the compression stroke of able during their extension strokes to compress fluid in the auxiliary chambers and discharge the same into the main chambers at or near the beginning of the compression stroke, and means whereby a portion or all of the fluid compressed in the auxiliary chambers may be bypassed back and forth between the auxiliary chambers in the respective cylinders.

10. In a fluid compressor of the character described a pair of cylinders, a piston in each cylinder, said pistons dividing each cyllnder into a mam and an auxiliary compression chamber; said pistons being operable during their extenslon strokes to 00111- press fluid in the auxiliary chambers and discharge the same 'into the main chambers 5 at or near the beginning of the compression stroke, a pipe connecting the auxiliary chambers and an adjustable valve in said pipe whereby a portion: dr -all 'ofthefluid compressed in the auxiliaiiy Chamber's may be vlay-passed baCkand forth between the auxiliary chambers in the respective cylinders.

'EDWARD A; RIX. 7 

